Positive locking terminal bushings for flexible pipe

ABSTRACT

This device is an adapter for joining flexible tubing run through a rigid pipe to such pipe and to continuing rigid piping, in both fluid-tight and mechanically positive relation. When the adapter is screwed on to the rigid pipe, the end of the pipe presses a non-metalic gasket into sealing relation with the protruding end of the flexible tubing and the adapter and forces a deformable metallic ring to contract about the tubing and crimp the tubing into a preformed groove in a metallic sleeve within the tubing. Stop means keeps the parts from exerting destructive pressure on the gasket.

United States Patent Nielsen, Jr.

POSITIVE LOCKING TERMINAL BUSHINGS FOR FLEXIBLE PIPE Anker J. Nielsen,Jr., 410 Bailey Rd., Holden, Mass. 01520 Filed: July 2, 1969 Appl. No.:847,775

lnventor:

Related US. Application Data Division of Ser. No. 522,877, Jan. 25,1966, abandoned.

1m. 01 ..F16l 9/14 Field 01 Search.....285/382.7, 15, 348, 339, 341,285/342, 343, 353, 340, 423, 243, 244, 246

References Cited UNITED STATES PATENTS 4/1941 Sander ..285/382.7 X10/1948 Woodling ..285/348 X 3/1968 Engel ..285/15 4/1943 Parker..285/382.7 X

[ 1 Oct. 24, 1972 2,349,180 5/1944 Lamont ..285/382.7 x 2,478,149 8/1949Wolfram et al.....285/382.7 x 3,368,831 2/1968 Phillipps.............285/382.7 x 3,375,025 3/1968 Engel ..285/348 FOREIGNPATENTS OR APPLICATIONS 1,257,824 2/1961 France ..285/342 PrimaryExaminer-Dave W. Arola Attorney-Robert K. Randall [571 I BSTRACTdeformable metallic ring to contract about the tubing and crimp thetubing into a preformed groove in a metallic sleeve within the tubing.Stop means keeps the .parts from exerting destructive pressure on thegasket.

3 Claims, 4 Drawing Figures Ill "5 IE7 1 N9 Patented ()ct. 24,1972

POSITIVE LOCKING TERMINAL BUSHINGS FOR FLEXIBLE PIPE This application isa division of my application, Ser. No. 522,877, filed Jan. 25, 1966 andnow abandoned.

This invention relates to devices for joining nonthreadable thin-walledflexible and deformable tubing or pipe to rigid pipe of fittings in amanner that will be both fluid-tight and mechanically fixed andpositive.

Such connecting means are widely used-in the repair or replacement ofexisting iron service pipe lines which require renewal because ofleakage, corrosion, or other reasons. It has become common practice toefiect renewalby running a continuous length of soft copper or plastictubing through the old iron house service pipe, thereby saving thelabor, cost, and delay of digging up and relaying buried service pipelines for gas, water or other fluids. All that remains to be done is tojoin one end of the tubing to the street main and the other end to themeter connection or other existing iron piping inside the building,which latter joining for safety and strength should be made within theiron pipe or fittings thereon. Especially in the case of gas pipes, thedelivery end of the tubing must be hermetically sealed to the interiorof the iron pipe or fitting, to prevent back-flow of gas through thespace between the two pipes, with eventual escape through leaks or atthe cut-off end of the iron pipe adjacent the main.

The present invention aims as indicated to provide improved means formaking mechanically positive and fluid-tight connection between a rigidpipe or fitting and a flexible pipe or tubing therein, in other words, apositive locking terminal tee, bushing or adapter for flexiblepipewithin a rigid pipe.

To this end, the invention provides a novel form of terminal bushingsand service head adapters, so-called, which includes in combination asleeve having a taper seat surrounding a pipe, a gasket within suchseat, a deformable continuous metallic ring to surround the pipe withinthe sleeve, a presser ring intervening between the gasket and thedeformable ring to press the gasket into gas-tight sealing relation tothe pipe, the presser ring having a taper seat occupied by thedeformable ring, an annular member around the pipe to press thedeformable ring into the taper seat and thereby contract this ring togrip the pipe, and screw means in connection with the sleeve to actuatethe rings.

A leading object of the invention is to control the pressure applied tothe gasket in installing it and to maintain such pressure duringservice. Hence novel provision is made both to protect the gasket fromdamage through vigorous tightening of the parts in installing, and alsoto reduce the likelihood of looseness arising from excessive caution inapplying, thus enabling these devices to be installed correctly bypersons of varying degrees of skill and familiarity therewith. Previousconnectors have been deficient in provision to prevent distortion of anddamage to the gasket by reason of cold flow of the component neoprene,rubber, or other gasket substance caused by too great mechanicallyapplied pressure, and incomplete confinement, and have provided tooscant leeway between too much and too little tightening of the parts toavoid occasional inadequate sealing pressure, in either situationresulting in leakage. Many times a T or other angle fitting, which mustbe turned to match the angle of the pipe to which it is joined, must gobeyond or stop short of the optimum gasket pressure when such is ascustomary a critical function of the screwing together of the parts. Itis of course impossible for the mechanic to observe or detect what ishappening to the gasket. These difficulties are overcome or minimized bythis invention.

The manner and means of applying the principle of the invention toattain these and other objects are as set forth hereinafter.

' An illustrative embodiment of the invention is shown in the drawings,in which:

FIG. 1 shows in side elevation the parts of a terminal adapter ofbushing type as modified to seal plastic tubing within an iron or otherrigid service pipe.

FIG. 2 is an axial sectional view of the terminal adapter bushing ofFIG. 1 applied to seal plastic tubing within an iron pipe, before theparts are tightened.

FIG. 3 is a similar view of the parts of FIG. 2, after the parts havebeen tightened.

FIG. 4 is an axial sectional view of the bushing of FIGS. 1 to 3.

The figures show an application of the invention principle to sealplastic tubing to the end of an iron pipe and thus provide for rigidconnection of the line to an iron pipe fitting. This adapter for plastictubing utilizes the end of the iron pipe 107 as the press to force ametallic compression ring 109 to press an non-metallic gasket 11 1 intoa taper seat 113 in a bushing 1 15, when the latter is screwed home byits thread 116 onto the thread 118 on the pipe. To support the plastictubing 108 against the inward pressure of the gasket as the latter iscompressed, a metallic sleeve 117 is first inserted in the tubing,having an outside diameter substantially equaling the interior diameterof the tubing. Thus the compressed gasket is able to make a gas-tightand watertight seal between the tubing and the bushing.

. To lock the plastic tubing 108 to the adapter bushing and thus to theiron pipe, i.e., to provide the mechanical seal, the sleeve 117,preferably of stainless steel, is formed with a peripheral groove 119into which the tubing is diverted radially inward. This is done by adeformable metal locking ring 121, initially larger than the tubingsdiameter, which second ring 121 is forced to contract radially by beingwedged into the conical or tapered interior 122 of the compression ring109, the locking ring 121 having a matching taper on its outside. Thelocking ring 121 is forced into the compression ring by a third ring orwasher 123 engaged by the end of the pipe 107 and having a taperedportion 125 matching the taper 122 inside the compression ring 109,enabling it to enter the ring 109 as shown in FIG. 9 and shrink thelocking ring inward about the plastic tubing, indenting the latter inannular manner and fore ing it down into the groove 119.

It'willbe noted that the bushing 115 has at its small end a radialshoulder or flange 12'! overlapping the end wall of the tubing 108, andthat the sleeve 117 has a flange 129 as wide as the wall thickness ofthe tubing. When the sleeve is inserted till this flange 129 meets theend wall of the tubing, with the latter projecting at least the lengthof the sleeve from the iron pipe, and when the bushing 115 is installedwith its shoulder 127 against this flange 129, the locking ring 121 isassured of being centered within the groove 119 made for the inwarddiversion of the wall of the tubing, by the cooperation of theselocating flanges as the bushing is screwed onto the iron pipe.

A turn or two of screw thread 131 loosely fitting the thread 116 in thebushing 115 enables the device to be delivered to the user as a unitwith all the parts assembled as shown in FIG. 2, (with the exception ofthe iron pipe 107 and the tubing 108,) the washer 123 lying loosely inthe recess 133 and preventing escape of the parts 109, 111, and 121, orimproper assembly. The user merely engages the bushings thread 116 withthe thread 118 of the iron pipe, with the sleeve 117 within the plastictubing, and screws the bushing on as far as it will 90.

To control the pressure applied to and maintained in the gasket 111 soas to avoid injury thereto, the compression ring 109 which applies thispressure is formed with a shoulder 135, FIG. 1, which engages theconfronting radial wall 137, FIG. 4, of the recess 133 and serves as astop limiting the extent of entry of the reduced end of this ring intothe taper seat 113, and thus determines the volume of the space intowhich the gasket is to be compressed, and the resulting pressure withinthe gasket.

The crimping of the locking ring 121 about the plastic pipe is similarlycontrolled by providing a shoulder 139, FIG. 1, which brings up againstthe radial face 141 of compression ring 109 to stop the entry of thetaper portion 125 into ring 109. It is through the coengagement of thisshoulder and this face that the sealing pressure applied by ring 109 tothe gasket is derived from the thrust of the end of the iron pipe 107 asit enters the bushing. This coengagement, and the encounter of shoulder135 with wall 137, determine the extent of such entry. Ring 121 wedgestightly and permanently in taper seat 122.

The invention is characterized by provision for applying adequatesealing pressure to the gasket while automatically protecting it fromdisabling or destructive excesses of such pressure.

While I have illustrated and described one form in which the inventionmay be embodied, I am aware that many modifications may be made thereinby any person skilled in the art, without departing from the scope ofthe invention as expressed in the claims. Therefore, I donot wish to belimited to the particular forms shown, or to the details of constructionthereof, but

What I do claim is:

1. A terminal bushing for connecting plastic tubing extending through arigid pipe to such pipe and to further fluid-conducting means in bothfluid-tight and mechanically positive relation, comprising incombination an internally screw-threaded tubular body to be fixed on thepipe and having a seat for the end of the tubing, a gasket in such seatto surround the tubing, a ring within the body to encircle the tubingand compress the gasket, and having a taper seat, a continuousdeformable metallic ring within the body to encircle the tubing andoccupy the taper seat, a grooved sleeve within the body to fit withinthe tubing, and an annular member within the body to surround the tubingand to be engaged by the end of the pipe and to force the deformablering into the taper seat and thus to contract this deformable ring tocrimp the tubing into the groove h S] e and lock the tubi totheb shin mi The c mbination aCCOI'EI IIg to clziim l m which co-engaging shoulderson the body and on the ring which compresses the gasket limit thepressure which can be applied to the gasket.

3. The combination according to claim 1 in which the annular member isexternally threaded for screwthreaded engagement with the body.

1. A terminal bushing for connecting plastic tubing extending through arigid pipe to such pipe and to further fluid-conducting means in bothfluid-tight and mechanically positive relation, comprising incombination an internally screw-threaded tubular body to be fixed on thepipe and having a seat for the end of the tubing, a gasket in such seatto surround the tubing, a ring within the body to encircle the tubingand compress the gasket, and having a taper seat, a continuousdeformable metallic ring within the body to encircle the tubing andoccupy the taper seat, a grooved sleeve within the body to fit withinthe tubing, and an annular member within the body to surround the tubingand to be engaged by the end of the pipe and to force the deformablering into the taper seat and thus to contract this deformable ring tocrimp the tubing into the groove in the sleeve and lock the tubing tothe bushing.
 2. The combination according to claim 1 in whichco-engaging shoulders on the body and on the ring which compresses thegasket limit the pressure which can be applied to the gasket.
 3. Thecombination according to claim 1 in which the annular member isexternally threaded for screw-threaded engagement with the body.